Other people, happily, disagree. About the world ending. About
what the Mayan writings said. Everything.

In any event...

You probably already know that some people believe the world is
going to end on Friday.

What you may not know is how the world is supposed to
end.

You will perhaps be relieved to hear that there is some
disagreement about this, too.

A lot of disagreement, actually.

Basically, there are four main theories:

We will get sucked into a black hole

The sun will pass through a "galactic plane" that
will cause everything to go haywire

Solar flares will reverse the poles and fry
us

We will smash into a planet called Nibiru

The planet Nibiru, you may be surprised to learn, was not
invented by L. Ron Hubbard, the man who invented Scientology.

You will probably be relieved to hear that astronomers are, to
put it mildly, highly skeptical that we will get sucked into a
black hole or fried or clobbered by another planet on Friday.
They also note that the sun "passing through galactic planes" is
something that takes millions of years.

Without further ado, therefore, here's how some people think the
world might end on Friday:

Some people have interpreted the galactic alignment
apocalyptically, claiming that when it occurs, it will somehow
create a combined gravitational effect between the Sun and the
supermassive black hole at
the center of our galaxy (known as Sagittarius A*), thus creating havoc on
Earth.[98]
Apart from the fact noted above that the "galactic alignment"
already happened in 1998, the Sun's apparent path through the
zodiac as seen from Earth does not take it near the true galactic
center, but rather several degrees above it.[72]
Even if this were not the case, Sagittarius A* is 30,000 light years from Earth and would have to
be more than 6 million times closer to cause any gravitational
disruption to Earth's Solar System.[99][100]
This reading of the alignment was included on the History Channel
documentary, Decoding the Past. However, John Major
Jenkins has complained that a science fiction writer co-authored
the documentary, and he went on to characterize it as
"45 minutes of unabashed doomsday hype and the worst kind of
inane sensationalism".[101]

Some believers in a 2012 doomsday have used the term "galactic
alignment" to describe a very different phenomenon proposed by
some scientists to explain a pattern in mass extinctions
supposedly observed in the fossil record.[102]
According to this hypothesis, mass extinctions are not
random, but recur every 26 million years. To account for this, it
suggests that vertical oscillations made by the Sun on its
250-million-year orbit of the galactic center
cause it to regularly pass through the galactic plane. When the
Sun's orbit takes it outside the galactic plane which bisects the
galactic disc, the
influence of the galactic tide is weaker. However, when
re-entering the galactic disc—as it does every 20–25 million
years—it comes under the influence of the far stronger "disc
tides", which, according to mathematical models, increase the
flux of Oort cloud comets into the inner Solar System by
a factor of 4, thus leading to a massive increase in the
likelihood of a devastating comet impact.[103]
However, this "alignment" takes place over tens of millions of
years, and could never be timed to an exact date.[104]
Evidence shows that the Sun passed through the plane bisecting
the galactic disc only three million years ago and is now moving
farther above it.[105]

A third suggested alignment is some sort of planetary conjunction occurring on 21 December 2012;
however, there will be no conjunction on that date.[106]
Multi-planet alignments did occur in both 2000 and 2010, each
with no ill result for the Earth.[107]Jupiter is the largest planet
in the Solar System; larger than all other planets combined. When
Jupiter is near opposition, the difference in
gravitational force that the Earth experiences is less than 1% of
the force that the Earth feels daily from the Moon.[108]

Most scientific estimates, however, say that geomagnetic
reversals take between 1,000 and 10,000 years to
complete,[111]
and do not start on any particular date.[112]
Furthermore, the U.S. National
Oceanic and Atmospheric Administration now predicts that the
solar maximum will peak in May 2013, not
2012, and that it will be fairly weak, with a below-average
number of sunspots.[113]
In any case, there is no scientific evidence linking a solar
maximum to a geomagnetic reversal, which is driven by forces
entirely within the Earth.[114]
Instead, a solar maximum would be mostly notable for its effects
on satellite and cellular phone communications.[115]
David Morrison attributes the rise of the solar storm idea to
physicist and science popularizer Michio Kaku, who claimed in an interview with
Fox News that a solar peak in 2012 could
be disastrous for orbiting satellites.[97]

Planet
X/Nibiru

Some believers in doomsday in 2012 claim that a planet called
Planet X, or Nibiru, will collide with or pass by Earth in
that year. This idea, which has appeared in various forms since
1995, initially predicted Doomsday in May 2003, but proponents
later abandoned that date after it passed without
incident.[116]
The idea originated from claims of channeling of alien beings and has been widely
ridiculed.[116][117]
Astronomers have calculated that such an object so close to Earth
would be visible to anyone looking up at the night sky.[116]

For what it's worth, we don't find any of these Armageddon
theories particularly compelling, at least not with respect to
Friday. But we've been wrong before...